What is a Square Footage Calculator?
A square footage calculator works out the floor area of a room or space from its length and width: area = length x width. This tool lets you add a row for every room or section, so you can total the area of a whole house, an apartment, a yard, or a job site at once. Each result is shown in the area unit you choose - square feet, square meters, square yards, acres, or hectares - and the same total is converted into the other common units so you can compare at a glance. It is built for flooring, painting, carpeting, tiling, landscaping, and real-estate listings, where you need both a reliable total area and a quick estimate of how much material or money the job will take.
How to Use
1. Enter the length and width of each room or section, optionally naming each row.
2. Pick a length unit (feet, meters, centimeters, inches, or yards) for your measurements.
3. Read each room's area and the running total; switch the output unit to see the total in m², yd², acres, or hectares.
4. Optionally enter a price per unit area to get the total cost, or the area one box/item covers to get the number of items needed.
5. For L-shaped or irregular spaces, split them into rectangles and add one row per rectangle.
Formula & Definition
For a rectangle: area = length x width.
Examples: 10 ft x 12 ft = 120 ft². Two rooms of 10 x 12 ft and 8 x 10 ft total 120 + 80 = 200 ft². A 3 m x 4 m room is 12 m², which equals about 129.167 ft².
Cost = total area x price per unit area; for example 100 ft² at $5/ft² costs $500.
Items needed = ceiling(total area / coverage per item); for example 200 ft² with a box covering 20 ft² needs ceil(200 / 20) = 10 boxes.
Internally every length is converted to meters, multiplied to get square meters, and then converted to your chosen area unit, so any mix of units is handled correctly.
Interpreting Results
The total is the net rectangular floor area; for real jobs add a waste allowance (often 5-10% for flooring and tile to cover cuts and breakage). Coverage figures on product packaging are nominal, so rounding the item count up is the safe choice this calculator makes. Remember that floor area is not wall area: for painting walls you need wall height x perimeter instead. Square feet and square meters describe the same surface in different units (1 m² ≈ 10.764 ft²), so use the output selector to match whatever your supplier or listing uses.
Frequently Asked Questions
How do I calculate square footage? ▾
Multiply length by width for each room and add them up. A 10 ft by 12 ft room is 120 ft²; add an 8 x 10 ft room and the total is 200 ft². The output unit can be switched to m², yd², acres, or hectares.
How do I handle an L-shaped or irregular room? ▾
Divide the space into rectangles, measure each, and add a row per rectangle. The calculator sums all rows into one total area.
How much flooring or paint do I need? ▾
Enter how much area one box or can covers and the tool returns the number of items needed, rounded up. For flooring and tile, add about 5-10% extra for cuts and waste.
How do I convert square feet to square meters? ▾
Divide square feet by about 10.764, or just switch the output unit. For example 200 ft² is about 18.58 m². This tool also shows the total in square yards, acres, and hectares.